Die retainer



Dec. 12, '1944.

A. o. MCCQLLUM 2,364,733

DIE RETAINER Filed June 4, 1943 2 Sheets-Sheet l MM N 0 wB N Q Patented Dec. 12, 1944 re srAres RATE-NT 1 OF F 2,364,733 DIE RETAINER Andrew 0. lVIcCollum, Detroit, Mich. Application June 4, 1943, Serial No. 489,648

1 Claim.

This invention relates to punches and dies, and more particularly to retainers therefor.

Broadly the invention comprehends a punch or operation on the parts during manufacture thereof shall be materially reduced.

A still further object of the invention is to provide a punch or die retainer which has the advantages of a positive lock for the punch or die,

is highly efficient in operation and yet of marked simplicity as a whole and in respect to each of its component parts to the end that its manufacture may be economically facilitated both as regards to parts and their assembly.

Other objects and structural details will be apparent from the subjoined description taken in connection with the accompanying drawings forming a part of this specification, and in which-- Fig. 1 is a vertical View, partly in section and partly in elevation, illustrating an assembly of a punch and die.

Fig. 2 is an enlarged view mostly in section illustrating a retainer secured to the'working head of a punching machine with a punch locked therein;

Fig. 3 is a sectional view substantially on line 3-3, Figure 2;

Fig. 4 is an end view of the retainer and punch;

Fig. 5 is a vertical sectional View partly in elevation illustrating a modification of the invention; and

Fig. 6 is a vertical sectional view partly in elevation illustrating another modification of the invention.

Referring to the drawings for more specific details of the invention, I0 represents the ram of a conventional-punching machine. The ram has secured thereto as by machine screws I2 a block or cylindrical member I4 of suitable hardness and finish. The block has a central or concentric bore I6, and fitted in the wall of the block adjacent the back thereof is a centering pin I8 having a portion of its perimeter extended into the bore IS.

The block or cylindrical member I4 also has a bore 20 therein inclined from the face of the member inwardly and opening into the bore I6. The bore 20 is partly threaded, as indicated at 22, and mounted for travel in the bore 20 is a lock pin 24 having a threaded portion 26 for cooperation with the threads 22 and a smoothly finished portion fitted snugly in the bore 20 and terminating in a cone-shaped freeend 28, and the outer or exposed end of the lock-pin is slotted as at'30 for the reception of a hand tool.

A punch 32 has a shank 34 provided with a circumferential slot 36 extended parallel to the axis of the punch and a recess 38 extended from the perimeter of the shank inwardly thereof and toward the butt of the shank. The recess 38 is defined by a wall portion complementary to the bore 20 and a shoulder portion 40 eomplementar to the conical end of the lock-pin. The lock-pin is backed outwardly until the pin is fully retracted from the bore I6. The shank of the punch is then inserted in the bore with the circumferential slot 36 in the shank receiving the centering pin I8. This aligns the recess 38 with the bore 20 in the retainer member I4. The lock-pin is then turned down until the conical end 26 thereon engages the shoulder 40. This provides a smooth bearing between the shank and the lock-pin, and thus facilitates in moving the shank against the ram with force and in retaining the punch against displacement.

A die shoe 42 has mounted thereon a retaining member 44 corresponding to the retaining member I4. The member 44 has a concentric bore 46, and threaded in the wall of the member 44 is a lock-pin 48 corresponding to the lock-pin 24. A die 50 fitted in the bore'46 has a recess 52 in its circumference for the reception of the lock-pin 48 and a concentric bore 54 for thereception of Another modification of the invention is illustrated in Fig. 6. In this embodiment of the invention a lock-pin 224 has a free end portion terminating in a fiat end 226, and the shank of the punch has a recess complementary to. the free end of the pin.

secure by Letters Patent is:

Having thus described the various features of i the invention, what I claim as new and desire to A die retainer comprising a cylindrical body having a concentric bore therethrough and a a partly threaded bore inclined from the face of the body inwardly to and in communication with the concentric bore, a centering pin in the body parallel to the vertical axis thereof and adjacent the top of the body having a part of its peripheral area extended into the concentric bore,

- and a lock-pin mounted for travel in the inclined bore having an accessible head slotted for the reception of a hand tool and a finished conical end.

ANDREW O. McCOLLUM. 

